<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link rel="stylesheet" href="style.css">
</head>

<body>
    <div class="single-demo">
        <div class="flip down" id="flip">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
        <div class="btn-con">
            <button id="btn1">向下翻+1</button>
            <button id="btn2">向上翻-1</button>
        </div>
    </div>
    <div class="clock" id="clock">
        <div class="flip down">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
        <div class="flip down">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
        <em>:</em>
        <div class="flip down">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
        <div class="flip down">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
        <em>:</em>
        <div class="flip down">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
        <div class="flip down">
            <div class="digital front number0"></div>
            <div class="digital back number1"></div>
        </div>
    </div>

    <script src="index.js"></script>
</body>

</html>